Third-order nonlinear optical response of Yb:YAG ceramics under femtosecond laser irradiation

Abstract Transparent ceramic laser materials, as an important alternate of traditional laser gain medium materials, have aroused much attention for their excellent performance. Here, we investigated the third-order nonlinear susceptibility of high quality transparent Ytterbium-doped Yttrium Aluminium Garnet (Yb:YAG) ceramics. Under an ultrafast femtosecond laser irradiation, we experimentally demonstrated the nonlinear optical limiting and self-focusing behaviors of Yb:YAG ceramic by Z-scan method at 800 nm. It was found that Yb:YAG ceramics exhibit a relatively small nonlinear refractive index (~3.8 × 10−20 m2/W) which exerts little dependence on the Yb3+ doping concentration and laser intensity. This work could illustrate the application potential of transparent ceramic under high-power condition and can also provide useful design guidelines for high power ceramic laser system.